1. Technical Field
The present invention relates generally to video transmission; and, more particularly, to program transmission to a recipient device via one or more communication networks.
2. Related Art
In recent years, other than merely providing broadband Internet services, Internet Service Providers (ISPs) have begun to think of more commercial opportunities in their Internet infrastructure investment. These commercial opportunities include streaming, downloading or buffer streaming audio and video content to recipient computers using via communication paths that often include the Internet infrastructure. Transfer of audio and video information using the Internet infrastructure involves compression encoding (hereinafter referred to as compression, encoding, or compression encoding) raw digital audio and video content and then packetizing the encoded audio/video at a source before transmission. The recipient computer de-packetizes and decodes the received data before presenting the resultant audio/video to a user. Audio and video may also be delivered to recipient video devices other than personal or laptop computers, such as televisions, personal digital assistants, mobile phones, pocket televisions, and personal video recorders, etc. via Internet channels. A typical term used to describe these commercial applications is Internet Protocol Tele-Vision (IPTV).
IPTV applications involve compression encoding and packetizing of the digital audio, video and data content at their sources prior to transmission. Sources of programming include commercial television broadcast programs, locally stored commercial and non-commercial music, locally stored recorded television programs, and movies, among other programming. The recipient device, such as an IPTV Set Top Box (IPTV STB), receives IP packets, de-packetizes the IP packets, decodes the encoded audio/video carried therein to raw audio/video, processes the raw audio/video to produce output video, and delivers the output audio/video to one or more recipient devices for presentation.
Encoding/decoding technologies currently available for audio/video encoding/decoding include standardized operations such as MPEG, JPEG, H.264, and MP3, for example. Such video encoding processes produce a sequence of encoded video frames. The sequence of video frames produced in the encoding process are packaged into data packets and transmitted to a recipient device. Some video encoding processes include generating, from raw video data, a spatially compressed independent frame, followed by spatially compressed reference (predictive) frames that only carry the difference video information between the independent frame and/or some of the preceding reference frames and current frame, and re-referencing (bidirectional predicted) frame that may only carry the difference video information between the independent frame and/or preceding and/or succeeding reference frames and current frame. This process is called time (temporal) compression/encoding. For example, with the MPEG4 compression standard, independent frames, referencing frames and re-referencing frames are referred to respectively as I, B and P frames.
Conventional compression techniques are used to save storage bandwidth. When transmitting such conventionally compressed media, any spatial compression error that occurs in an Independent frame may persist in subsequent reference and re-reference frames. In addition, IPTV STBs may not be able to recover/reconstruct an independent frame or a re-reference frame, if some packets carrying the frame(s) that are lost in the Internet channels. Also, since, at the source end, typically, compression employed is based upon a highest presumed quality of recipient devices (such as High Definition Tele-Visions—HDTVs—or surround sound audio systems). Thus, even though compression operations reduce the size of the data transmitted, huge amounts of Internet channel resources may be utilized even when a recipient device is incapable of benefiting from the high quality audio/video content. Another problem relating to the default transmission of highest quality video is that the recipient device needs huge buffering resources and extensive processing resources when operating upon the received video and audio information. These storage and processing demands placed upon the recipient device are required even though the recipient device may have its own storage, processing, and display limitations.
These and other limitations and deficiencies associated with the related art may be more fully appreciated by those skilled in the art after comparing such related art with various aspects of the present invention as set forth herein with reference to the figures.